With the development of semiconductor integrated circuits, higher requirements are raised for the performance of a semiconductor device, especially the speed of the device. In order to improve the performance of a semiconductor device, techniques have been proposed to introduce mechanical stress in the semiconductor device, e.g. in a channel of a transistor. These techniques of introducing stress comprise using a stress liner on top and embedding a semiconductor into a source/drain region.
However, these techniques of introducing stress increase the complexity of the process for manufacturing a semiconductor device, and at the same time cannot be applied in various integrated circuits due to process limitation.